Fault code lookup

PowertrainP0400

Caution

Severity: Caution - get it checked when you can

Exhaust Gas Recirculation Flow

41 brands affected · Generic SAE J2012 description.

Key terms: EGR: exhaust gas recirculation, which cuts harmful gases · SAE J2012: the standard generic code list · Powertrain: engine, transmission and emissions

1What it means in plain English

The exhaust gas recirculation (EGR) system is not flowing the amount of exhaust gas the engine computer expects.

2Common causes

  1. Clogged EGR passage or valve
  2. Faulty EGR valve
  3. Damaged or leaking EGR pipe
  4. Faulty EGR position sensor
  5. Carbon build-up in the intake

3Can I drive?

Caution · drive with care

Usually safe to drive. Rough idling, pinging, or failed emissions tests can follow; have it checked before an inspection.

This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.

4Brand data 41

BrandCodeDescriptionSystem
Ashok Leyland CVP0400Exhaust Gas Recirculation Flow SAEPowertrain
BAIC MotorP0400Exhaust Gas Recirculation Flow BrandPowertrain
Mercedes-BenzP0400Exhaust Gas Recirculation Flow SAEPowertrain
BMWP0400Exhaust Gas Recirculation Flow BrandPowertrain
BYDP0400EGR system BrandPowertrain
CheryP0400EGR system BrandPowertrain
ChryslerP0400Exhaust Gas Recirculation (EGR) system performance BrandPowertrain
DaewooP0400System fault 1 BrandPowertrain
DaihatsuP0400EGR flow abnormal BrandPowertrain
DFFSP0400Exhaust Gas Recirculation Flow BrandPowertrain
DFFXP0400EGR system BrandPowertrain
DFXKP0400EGR System: Malfunction BrandPowertrain
EOBDP0400EGR 'A' flow BrandPowertrain
FordP0400Exhaust Gas Recirculation Flow SAEPowertrain
GeelyP0400EGR system BrandPowertrain
GMP0400Exhaust Gas Recirculation Flow BrandPowertrain
Great WallP0400EGR system BrandPowertrain
HafeiP0400EGR system BrandPowertrain
HoldenP0400Exhaust Gas Recirculation (EGR) Flow Incorrect BrandPowertrain
HondaP0400Exhaust Gas Recirculation Flow SAEPowertrain
HyundaiP0400Exhaust Gas Recirculation Flow SAEPowertrain
IsuzuP0400Exhaust Gas Recirculation Flow SAEPowertrain
Land RoverP0400Exhaust Gas Recirculation Flow SAEPowertrain
MahindraP0400EGR SYSTEM BrandPowertrain
MazdaP0400Exhaust Gas Recirculation Flow SAEPowertrain
MitsubishiP0400EGR system BrandPowertrain
NissanP0400Exhaust Gas Recirculation (EGR) system BrandPowertrain
OpelP0400Exhaust Gas Recirculation Flow BrandPowertrain
PeroduaP0400EGR flow abnormal BrandPowertrain
PeugeotP0400Exhaust Gas Recirculation Flow SAEPowertrain
ProtonP0400EGR system BrandPowertrain
RenaultP0400EGR system BrandPowertrain
SaabP0400Exhaust Gas Recirculation Flow BrandPowertrain
MG (SAIC)P0400Exhaust Gas Recirculation Flow BrandPowertrain
SmartP0400Exhaust Gas Recirculation Flow SAEPowertrain
SprinterP0400Exhaust Gas Recirculation Flow SAEPowertrain
SubaruP0400EGR System Malfunction BrandPowertrain
SuzukiP0400Exhaust gas recirculation flow malfunction detected BrandPowertrain
TataP0400EGR Air Error BrandPowertrain
ToyotaP0400Exhaust gas recirculation (EGR) valve flow too low/too high BrandPowertrain
VolkswagenP0400EGR system: malfunction BrandPowertrain

Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.

5Extended variant codes 1

These 7-character codes are manufacturer-specific variants of P0400 and may be reported by some scan tools.

BrandCodeDescriptionSystem
SsangYongP040000EGR control valve fault BrandPowertrain

6Related codes

  • P0401 Exhaust Gas Recirculation Flow Insufficient Detected
  • P0402 Exhaust Gas Recirculation Flow Excessive Detected
  • P0403 Exhaust Gas Recirculation Circuit
  • P0404 Exhaust Gas Recirculation Circuit Range/Performance
  • P0405 Exhaust Gas Recirculation Sensor A Circuit Low
  • P0406 Exhaust Gas Recirculation Sensor A Circuit High
  • P0407 EGR Sensor B Circuit Low
  • P0408 EGR Sensor B Circuit High
  • P0409 Exhaust Gas Recirculation Sensor A Circuit
  • P040A Oil gauge failure
  • P040B EGR Temperature Sensor A Circuit Range/Performance
  • P040C EGR Temperature Sensor A Circuit Low

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